The present invention relates to a data recording controller for controlling the recording of a data recorder.
Devices for recording a large capacity of data on optical discs have become widely used. Address information indicating write positions of data are normally provided in an optical disc. A compact disc (CD) has a single spiral recording track for recording information. The information device uses a writable recording medium, such as a compact disc-recordable (CD-R) or a compact disc rewritable (CD-RW) The recording track of a writable CD includes grooves formed in flat surfaces (lands) of the disc. Each groove is slightly wobbled and thus referred to as a wobble. Absolute time in pre-groove (ATIP), which corresponds to the cyclic change of the wobble, is written to the optical disc. The recording track is traced to read the ATIP information and obtain absolute time information of the present recording position (address). The absolute time information is address information designating a position, or write position, on the disc.
Wobbles are also preformed in a digital versatile disc (DVD), which has a larger storage capacity than a CD.
However, the wobbles of a DVD do not necessarily include address information. In a DVD, sections containing address information, or land pre-pits (LPPs) are arranged on the recording track at predetermined intervals. The address information of the LPPs does not represent the absolute time information of recording track positions and are sector numbers, which are successively added.
In this manner, the address information is configured differently in a CD and a DVD. Further, the format of the address information and the method for modulating the address information differs between a CD and a DVD Accordingly, referring to FIG. 1, a data recording-reproducing device that records data on and reproduces data from both CDs and DVDs includes a controller 50, which controls a CD data recording-reproducing section and a DVD data recording-reproducing section.
When writing data to a DVD, a head 102 picks up a signal from a disc 101. An LPP detection circuit 113 extracts an LPP signal 113a from the signal and provides the LPP signal 113a to an LPP decoder 114. The LPP decoder 114 extracts LPP data 114a, which includes address information of the disc, from the LPP signal 113a and provides the LPP data 114a to a DVD write timing generation circuit 115. An 8-16 modulation circuit 116 modulates write data in accordance with a command from the DVD write timing generation circuit 115 and provides the modulated write data to a DVD write strategy circuit 117. The DVD write strategy circuit 117 generates a pulse signal (write signal), which corresponds to the output intensity of a laser beam, from the 8-16 modulated write data. The pulse signal is sent to a write signal gate 119 via a selector 118, which selects an input signal in accordance with a switch control signal. The write signal gate 119 provides the selected pulse signal to the head 102 in accordance with a timing signal received from the DVD write timing generation circuit 115. Data is written to a DVD in this manner.
When the recording-reproducing device of FIG. 1 writes data to a CD, the head 102 picks up a signal from the disc 101. A wobble detection circuit 123 extracts a wobble signal 123a from the signal and provides the wobble signal 123a to an ATIP decoder 124. The ATIP decoder 124 extracts ATIP data 124a, which includes address information of the disc, from the wobble signal 123a and provides the ATIP data 124a to a CD write timing generation circuit 125. An 8-14 modulation circuit 126 modulates write data in accordance with an instruction from the CD write timing generation circuit 125 and provides the modulated write data to a CD write strategy circuit 127.
The CD write strategy circuit 127 generates a pulse signal (write signal), which corresponds to the output intensity of a laser beam, from the 8-14 modulated write data. The pulse signal is sent to the write signal gate 119 via the selector 118. The write signal gate 119 provides the selected pulse signal to the head 102 in accordance with a timing signal received from the CD write timing generation circuit 125. Data is written to a CD in this manner.
The process for reading data from a recording medium with the recording-reproducing device of FIG. 1 will now be discussed.
Referring to FIG. 2A, when the recording-reproducing device reads data from a DVD, a signal read by a pickup 130 is amplified by an RF amp 131. A binary circuit 132 converts the amplified signal to digital data of 0 or 1. A read channel circuit 133 generates a read channel clock signal, which has a predetermined frequency, from the digital data, samples the digital data in accordance with the reach channel clock signal, and restores 16 bits of digital data. A DVD synchronization detecting circuit 134 detects a synchronizing signal from the restored digital data to extract data, which is subject to reading. An 8-16 demodulation circuit 135 demodulates the extracted data to 8 bits of data. The demodulated data is sent to a DRAM 137 via a buffering circuit 136
Referring to FIG. 2B, when the recording-reproducing device reads data from a CD, digital data read and sampled from a CD is synchronized by a CD synchronization detection circuit 144 and demodulated by an 8-14 demodulation circuit 145. Other processes are performed in the same manner as in FIG. 2A.
As described above, the controller 50 of a recording-reproducing device that reads data from and writes data to both DVDs and CDs requires an exclusive circuit for each type of recording medium that has a different recording format. Thus, the controller 50 has a complicated configuration. Further, a DVD exclusive recording-reproducing device does not include processing circuits that are unique for CDs and thus cannot be used for CDs, which are popular and economic.